Background and importance The effect of taking drugs with the capacity to develop anticholinergic adverse effects, both peripheral (urinary retention, constipation, etc) and central (cognitive/functional disorders), is cumulative and may be different depending on the measurement scale used. In the psychiatric population, this effect may be greater due to the type of medication used.

Aim and objectives To analyse the prevalence and risk of anticholinergic burden (AB) in hospitalised psychiatric patients through the use of different calculation scales, and comparison between them to determine the most indicated in our psychiatric sample. To establish the most prescribed antipsychotic medications, and to determine if there are differences between the short stay unit (CSU) and the long/medium stay ward (LSW).

Material and methods A cross sectional study was conducted in psychiatric patients admitted in the last month. Variables collected were: demographic (age, sex), hospitalisation unit, number of drugs with AB and their anticholinergic risk according to the following scales: anticholinergic drug scale (ADS), anticholinergic risk scale (ARS), drug burden index (DBI), anticholinergic cognitive burden scale (ACB), Chew’s scale (Chew), anticholinergic activity scale (AAS), anticholinergic load scale (ALS), clinician rated anticholinergic scale (CrAS) and Duran’s scale (Duran). The variables were obtained from the electronic medical records, and the AB and risk (no risk/low/medium/high) were calculated according to the aforementioned scales, using the AB calculator tool.

Results 67 patients (63% women) were treated with drugs with anticholinergic effects; mean age was 42.9 years. All patients had been prescribed some drug with AB (average number 5). Average number of drugs with AB in the CSU was 3.8 compared with 5.5 in the LSW (p<0.05). The AB on each scale was: 4.3 (high) with ACB; 3.7 (medium) with Chew; 2.3 (medium) with CrAS; 3.3 (medium) with AAS; 2.3 (medium) with ARS; 2.7 (high) with Duran; 2.9 (high) with DBI; 5.3 (high) with ADS; and 1.8 (medium) with ALS. The most prescribed drugs with anticholinergic activity were: benzodiazepines (88.1%), olanzapine (46.3%), antidepressants (41.8%) and quetiapine (37.3%).

Conclusion and relevance The number of psychiatric patients treated with drugs with anticholinergic effects was very high (100%), and statistically higher in the LSW than in the CSU. Studies are needed to determine which of these scales is the most useful to apply in our population. The drugs with anticholinergic activity most prescribed were, by far, benzodiazepines. Withdrawing (progressively), replacing pharmacological treatment (if it cannot be suspended) or reducing the dose (minimum effective dose) would be valid strategies to reduce the anticholinergic burden.

Conflict of interest No conflict of interest